Metering and flow control valve

ABSTRACT

A valve for controlling the rate of fluid flow therethrough by rotating a rotor about a spindle having an inlet bore in communication with an eccentrically oriented o-ring set into an eccentrically oriented slot formed in the rotor. The perimeter of the eccentric slot is modified to provide customized unique fluid flow response curves.

FIELD OF THE INVENTION

This invention relates generally to valves for controlling fluid flow.More particularly, the invention relates to valves for metering fluidflow manually and with electronic means.

BACKGROUND OF THE INVENTION

Almost all valves consist of a fixed body containing a hole or portcovered by a sealing element. This sealing element (valve) can uncoverthe port to varying degrees and allow fluid to flow. The arrangement ofthese elements generally takes the form of axial pairs (lift valve),turning pairs (rotary valve motion), screw pairs (helical valve motion),and sliding pairs (gate valve). These valve elements are acceptedpractice, have been utilized for centuries and there are manymanufacturers using these principles to accomplish the same task.

The miniature valve market, typified by manufacturers like Clippard,Pneumadyne and Whitey, offer a variety of metering valves. However, allare needle valve designs. Needle valves are capable of precise meteringbut have several drawbacks. A needle valve is an axially arranged deviceand its accommodation to applications usually require shapes, ports andmanufacturing complexity. In order to adjust flow rates a tapered needleis screwed in and out of a circular aperture enabled by threadscoaxially constructed along the needle shaft. The resulting spaceoffered as a flow passage is at best an annulus (and often deterioratesto a crescent) where the area varies with axial needle position createdby screw threads. Area is an arithmetic function of the radii squaredand accordingly the range of linear sensitive control is onlyapproximate and at the same time narrow. Also, unless the same materialis used throughout, the valve differential expansion leads to aninherent lack of temperature compensation. Furthermore, the tinyclearances generated clog easily and good filtration of the medium isrequired. Unless exceptionally complex shapes, and/or threads and/orcontrols are used in the design of the valve, the flow through needlevalves is not a linear function of needle position. The needlesthemselves require precision manufacturing techniques. Since the needlerequires several rotations from off to fully open they do not lendthemselves to rapid automatic operation. It is also very difficult toarrange a needle valve for “fail safe” operation, i.e., should the valveactuator loose power, the valve cannot be spring or gravity returned tothe off position. Moreover, the needle and seat surfaces are subject todamage due to brinelling scuffing and scoring.

Accordingly, there is a need for a valve that solves the problemsassociated with needle, ball and butterfly, valves. It is among theobjects of the invention to provide a valve that simplifiesmanufacturing requirements. Another object of the invention is toprovide a valve the provides a linear response curve. A further objectis to provide a valve that allows for customized flow resistance versusvalve position. These and other objects will become apparent from areading of the following summary and detailed description of theillustrative embodiment.

SUMMARY OF THE INVENTION

The invention described herein overcomes several of the drawbacks foundwith competing devices and offers added versatility and ease ofmanufacture. The valve is an extreme case of rolling hypocycloidalmotion which is the geometric name given to a circle rolling inside alarger circle. In this configuration, the inner circle is 5 to 20%smaller in diameter than the outer circle that includes or contains thecontrol “O” ring. Thus, the seal device not only exhibits thishypocycloidal action but also has a small amount of sliding.

The larger diameter or circle utilizes the inner diameter of an “O”-ringas the throttling or control surface, captured in either a plaincircular groove or a uniquely shaped groove as the controlling valveelement. This “O”-ring/groove combination is eccentric to the centerspindle that contains the valve port and also serves as a channel fordirecting the fluid to be metered. When off, due to the local squeeze orflattening of the “O”-ring the sealing is accomplished by covering orblocking the valve port and produces a bubble-tight seal. A the sleevecontaining the “O”-ring/groove is rotated about the spindle, theeccentricity of the groove allows the “O”-ring to gradually uncover thevalve port thereby permitting flow of the upstream pressurized fluid.The extreme positions start from 0 degrees where the port(s) are fullycovered to about 180 degrees where the maximum amount of clearance abovethe port(s) exists. As rotation continues beyond 180 degrees the flowbegins to be restricted until at the full 360 degrees the port(s) arecompletely covered. In other words, the full range of flow modulationtakes place over 180 degrees of the outer sleeve rotation and thecontrol is the same for either direction of rotation. In practice, themost useful range of rotation is usually about 90 degrees from fully“off” to maximum useful flow. The geometric nature of the eccentricgroove and the proportions of the “O”-ring cross sections with respectto the port sizes create a flow pattern that is approximately sinusoidalbut approaching linear with respect to the angle of rotation.

In practice, due to tolerances, deformation of the “O”-ring sealeffective control range is about 90 degrees ( 1/4 turn) of rotation,where the valve goes from shut to fully open. This arrangement hasnumerous advantages over needle valve designs. Further, by machiningunique shapes for the gland containing the “O”-ring (easily achievedwith modern CNC (computer numeric control) machine tools), theresistance curve of the valve can be tailored to the application. Inaddition, the sealing surfaces tend to be inherently self-flushing orcleaning, tolerant of debris and insensitive to vibration. In choosingthe port of the appropriate size, the maximum resistance of the valvecan set to the desired valve. Unlike other ¼ turn valve types (butterflyvalves and ball valves), the invention has precision incrementalmetering characteristics. The internal geometry of ball valves andbutterfly valves causes them to open and close very abruptly and thusmakes them ill suited to accurately meter flow rates (although they areoften used in such applications).

The invention has an inherently gradual open/close cycle. Since it canbe shut off within ¼ turn in one embodiment, the valve can be made“fail-safe” by the addition of a spring return. All of these featurescan be achieved by modification of two machined parts.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view of a sleeve valve assembly accordingto one embodiment of the invention.

FIG. 2 is a plan view of a spindle according to one embodiment of theinvention.

FIG. 3 is a top view of a spindle according to one embodiment of theinvention.

FIG. 4 is a side sectional view of a rotor taken along line A-A in FIG.5 according to one embodiment of the invention.

FIG. 5 is a top view of a rotor according to one embodiment of theinvention.

FIG. 6 is a bottom view of rotor according to one embodiment of theinvention.

FIG. 7 is a side elevational view of a cap according to one embodimentof the invention.

FIG. 8 is a top view of a cap according to one embodiment of theinvention.

FIG. 9 is a graph of flow rates achieved when employing a sleeve valveconstructed in accordance with one embodiment of the invention.

FIG. 10 is a side elevational view of a metering valve/motor assemblyaccording to one embodiment of the invention.

FIG. 11 is a side elevational view of a coil stator plate assembled intoa housing with a wire lead pass subassembly according to one embodimentof the invention.

FIG. 12A is an exploded view of a coil/stator plate assembly accordingto one embodiment of the invention.

FIG. 12B is a side view of a coil/stator plate assembly according to oneembodiment of the invention.

FIG. 13 is a top plan view of a twelve pole stator plate according toone embodiment of the invention.

FIG. 14 is a side elevational view of a stator plate according to oneembodiment of the invention.

FIG. 15 is a side view of a bifilar wound, center-tapped coil accordingto one embodiment of the invention.

FIG. 16 is an end view of a motor coil with wire leads according to oneembodiment of the invention.

FIG. 17 is a side sectional view of a rotor/spindle assembly accordingto one embodiment of the invention.

FIG. 18 is a top view of a rotor/spindle assembly according to oneembodiment of the invention.

FIG. 19 is a side plan view of a valve rotor according to one embodimentof the invention.

FIG. 20 is a top view of a valve rotor according to one embodiment ofthe invention.

FIG. 21 is a bottom view of a valve rotor according to one embodiment ofthe invention.

FIG. 22 is a side sectional view of a spindle according to oneembodiment of the invention.

FIG. 23 is a sectional view of a spindle exit port according to oneembodiment of the invention.

FIG. 24 is an end view of a spindle according to one embodiment of theinvention.

FIG. 25 is a side sectional view of a twelve pole rotor magnet accordingto one embodiment of the invention.

FIG. 26 is a top view of a twelve-pole rotor magnet according to oneembodiment of the invention.

FIG. 27 is a side view of a gland nut according to one embodiment of theinvention.

FIG. 28 is a top view of a gland nut according to one embodiment of theinvention.

FIG. 29 is a top view of a wire pass through seal according to oneembodiment of the invention.

FIG. 30 is a side view of a wire pass through seal according to oneembodiment of the invention.

FIG. 31 is a top view of a seal support plate according to oneembodiment of the invention.

FIG. 32 is a side view of a seal support plate according to oneembodiment of the invention.

FIG. 33 is a side sectional view of a metering valve housing accordingto one embodiment of the invention.

FIG. 34 is a top view of a metering valve housing according to oneembodiment of the invention.

FIG. 35 is a bottom view of a metering valve housing according to oneembodiment of the invention.

FIG. 36 is a top view of a metering valve housing seal cap according toone embodiment of the invention.

FIG. 37 is a side view of a metering valve seal cap according to oneembodiment of the invention.

FIG. 38 is a retaining nut according to one embodiment of the invention.

FIG. 39 is a side view of a retaining nut according to one embodiment ofthe invention.

FIG. 40 is a side sectional view of a die-cast metering valve housingaccording to one embodiment of the invention.

FIG. 41 is a bottom view of a die-cast metering valve cap according toone embodiment of the invention.

FIG. 42 is a top view of a die-cast metering valve cap according to oneembodiment of the invention.

FIG. 43 is a top view of a die-cast metering valve cap according to oneembodiment of the invention.

FIG. 44 is a side view of a die-cast metering valve cap according to oneembodiment of the invention.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENT

As shown in FIG. 1, in its broadest overall aspect, the metering valve(shown generally as 1) is essentially a sleeve valve comprising a rotor2 secured to a rotor gear 4 at one end and a cap 6 at the opposite end.A spindle 8 is fitted into and freely slides within apertures formed inrotor 2 and cap 6.

Referring to FIGS. 1-3, spindle 8 has a longitudinal inlet bore 10 and alongitudinal outlet bore 12 situated at opposite ends of spindle 8. Theinner walls of bores 10 and 12 are provided with threading 11(preferably 10-32) for receiving fluid conduit nipples or barbs (notshown). Inlet bore 10 has a radial inlet aperture 14 that extendsradially outwardly from inlet bore 10 to an outer wall 16 of spindle 8.Outlet bore 12 has a radial outlet aperture 18 that extends radiallyoutwardly from outlet bore 12 to outer wall 16. Alternatively, spindle 8can be provided with multiple radial inlet and/or outlet apertures thatcan be positioned at various points along the length of inlet and outletbores 10 and 12. For ease of handling, a hexagonal top 20 is provided onspindle 8 to allow spindle 8 to be torqued into a mounting platedescribed in detail below.

Referring to FIGS. 1 and 4-6, rotor 2 has a substantially cylindricalrotor body 22 within which is formed a spindle bore 24 dimensioned tofit snugly around outer wall 16 of spindle 8 and symmetrically about thelongitudinal axis of rotor body 22. A fluid cavity bore 26 is providedin a longitudinally central region of rotor 2, concentrically withspindle bore 24, to provide fluid communication between inlet aperture14 and outlet aperture 18. Formed proximal to a bottom end of rotor 2 isrotor/spindle o-ring bore 27. Formed in the top end of rotor 2 iseccentric bore 28. Eccentric bore 28 is situated in rotor 2 so that itis coplanar with inlet aperture 14 when assembled. The radial depth ofeccentric bore 28 is set so that the o-ring placed in bore 28, asdescribed below, is sufficiently compressed to provide a leak-tight sealof inlet aperture 28. A rotor o-ring bore 30 is formed proximal to thebottom end of rotor body 22.

Referring to FIGS. 1, 7 and 8, rotor cap 6 has a substantiallycylindrical cap body 34 and a cap spindle bore 32 dimensioned to snugglyfit against spindle outer wall 16. Formed proximal to a top end of cap 6and concentrically with bore 32 is cap o-ring bore 36. Formed proximallyto a bottom end of cap 6 and in concentric relation with spindle bore 32is rotor o-ring bore 38. Formed on the bottom end of cap 6 and inconcentric relation to spindle bore 32 is rotor-receiving bore 40. Bore40 is dimensioned to fit snuggly against an outer wall of rotor 2.

Referring to FIG. 1, rotor 2 is press fit into a hub 42 of rotor gear44. Rotor gear 44 is formed with gear teeth 46 for engaging gear teeth50 of drive gear 48. Rotor gear 44 and drive gear 48 are preferably madeof Delrin®. Drive gear 48 is attached to shaft 52 of motor 54. Motor 54is preferably a unipolar stepping motor.

To orient motor 54 and drive gear 48 to rotor gear 44, mounting plate 4is provided. A motor bore (not shown) is formed in mounting plate 4 toallow passage of shaft 52 through plate 4. Motor 54 is secured to thebottom of plate 4 with mechanical fasteners such as screws (not shown).Rotor gear 44 is secured to the top of plate 4 with mechanical fasteners(not shown). A plate spindle bore 58 is formed concentric with themounting location of rotor gear 44 to allow for passage of the bottomend of spindle 8. A plate o-ring slot 60 is formed in plate 4,concentric with plate spindle bore 58.

To assemble valve 1, appropriately sized o-rings (preferably formed frombuna-n) are fitted into the various o-ring slots to provide leak-tightjunctures between the various valve components. Preferably, the o-ringsare toroidally shaped but may be square, rectangular or any otherregular or irregular geometric cross-sectional shape. O-ring 62 securedinto o-ring slot 60 to provide a seal between plate 4 and spindle 8.O-ring 64 is placed into rotor/spindle o-ring bore 27. O-ring 66 isplaced into cap o-ring bore 36 to seal between spindle 8 and cap 6.O-ring 68 is placed into rotor o-ring bore 38 to seal between theinterface of cap 6 and rotor 2. O-ring 70 is placed in eccentric bore 28and provides a seal to inlet aperture 14 that is located on the samehorizontal plane as bore 28.

The eccentric orientation of bore 28 to spindle 8 causes the sealprovided by o-ring 70 to be released or engaged in a substantiallylinear fashion depending upon the rotational orientation of rotor 2 tospindle 8. In a preferred embodiment, spindle 8 is dimensioned so thatit is engaged to and stationary with respect to plate 4 via o-ring 62.The offset of bore 28 can be adjusted to allow for the angular range ofmotion needed to fully open and fully close inlet aperture 14 to be fromabout 90° to about 180°. The range of motion to accomplish full closureor full open conditions can be effectuated in either clock-wise orcounter-clockwise rotation of rotor 2 about spindle 8.

Fluid flows through inlet bore 10 and out inlet aperture 14 into thecavity formed between the outer wall 16 of spindle 8 and fluid cavitybore 26. The fluid then enters into outlet aperture 18 and into outletbore 12. All of the o-rings contribute to the integrity of the fluidflow path. To impede fluid flow, one merely needs to rotaterotor/cap/rotor gear assembly about spindle 8 to alter the relationshipand contact between o-ring 70 and inlet aperture 14.

In operation, the relationship of o-ring 70 to inlet aperture 14 issimilar to the communication between a bicycle tire and a substrate. Aninkblot made by the bicycle tire on a flat (or convex) surface is shapedlike an elongated diamond terminating as a sharp point on either end. Asthe tire rolls along a flat or convex surface, the diamond shape movesalong the surface in the direction the tire is rolling. By placing, forexample, an aperture or hole somewhat smaller in diameter that thecross-sectional diameter of the tire in mid plane, the tire will coverthe hole completely when directly above the hole. As the tire continuespast the hole, it gradually uncovers the hole. Initially, a partial areaof the aperture becomes exposed because the hole is only partly maskedand is bisected by the point of the diamond pattern. Continued rollingwill eventually uncover the hole completely. The change in area of theexposed hole approaches a linear pattern unlike the effect of the needlevalves described above where the exposed area of the round hole is aquadratic function.

FIG. 9 illustrates the relative flow of fluid through the valve atvarious angular displacements of rotor 2 to spindle 8 and at variousinlet aperture diameters. The aperture diameters are in thousandths ofan inch, e.g., 062 in the graph key represents an aperture diameter of62 thousandths of an inch. As can be seen in the graph results, thegeometric nature of the eccentric groove and the proportions of o-ring70 cross sections with respect to port sizes create a flow pattern thatis approximately sinusoidal but approaching linear with respect toangular displacement of o-ring 70 relative to inlet aperture 14.

It has now been discovered that the sinusoidal aspects of the flowpattern can be modified almost indefinitely by machining uniqueperimeter patterns in eccentric bore 28 at selected points along theperimeter of the bore. One such perimeter alteration is shown in FIG. 5.A scalloped portion 72 is removed from the perimeter of eccentric bore28 at approximately 30° from a closed position. The results of themodification are shown in FIG. 9 on the plot for the 062 test run. Atthe 30° point, designated A, what was previously sinusoidal closelyapproximates a linear flow rate or change per angle of rotation. Such amodification can be made at any point along the effective sealing areaof the eccentric bore to modify the flow rate of change.

In an alternate embodiment (not shown), the metering valve may beconverted to a flow control valve by making a longitudinal connectionbetween inlet bore 10 and outlet bore 12 and adding a check valve inbetween the two ends of spindle 8. In a further embodiment, because ofthe relatively short rotational path to travel from a fully openposition to a fully closed position, a return spring can be providedbetween rotor 2 and spindle 8 (not shown) to provide fail safeoperation.

In a yet further embodiment, the metering valve can be incorporated intothe rotor of a motor, such as for illustrative purposes, a step motor,to provide precise control over fluid flow in a compact assembly. FIG.10 shows a metering valve/step motor assembly 100 comprising in its mostgeneral aspects, a spindle 118 concentrically arranged in a rotor 112that is in turn concentrically arranged in a multi-pole rotor magnet120. The combination of rotor magnet 120, rotor 112 and spindle 118comprise a rotor assembly 125.

Rotor assembly 125 is concentrically arranged in stator assembly 130.Stator 130 comprises in one embodiment, a plurality of wire coils 132concentrically arranged in a series of stator plates 134 that house thecoils 132. Stator 130 and rotor assembly 125 are situated in a meteringvalve housing 135 that has a series of openings for receiving variousfluid transport fittings as well as a watertight housing seal cap 136.Seal cap 136 is secured in place with a housing retaining nut 138. Eachmajor component of the metering valve will not be described in detailwith respect to particular embodiments.

The following illustrated embodiment relates to a twelve pole stepmotor. It is to be understood that the invention contemplates the use ofmotors having various pole configurations. As shown in FIGS. 11-16,stator assembly 130 comprises a series of interlocking stator plates 134that are generally circular in shape. Stator plates 134 have a circularbase 140, an axially projecting outer wall 141 formed with axiallyprojecting stator tabs 142 and stator notches 144 that are preferablydiametrically opposed in pairs and dimensioned so that the stator tabs142 of one stator plate 134 will lock into the stator notches 144 of anadjacent stator plate 134 to form an annular cavity for housing a wirecoil 132 as shown in FIG. 12B. Stator plates 134 have a central statoraperture 146 for receiving rotor assembly 125.

Extending axially from the perimeter of stator aperture 146 are a seriesof internal tabs 150 dimensioned and spaced apart so that the distancebetween adjacent internal tabs 150 is equal to the width of theindividual internal tabs 150. Internal tabs are configured so that theinternal tabs 150 of two stator plates 134 are capable of interlockingalong with the stator tabs 142 and stator notches 144 to further form anannular cavity to receive coil 132. Preferably two wire chases or slots152 are provided in stator base 140 and outer wall 141 to accommodatewire leads from coils 132. Slots 152 are situated on stator plates 134so as to align with other slots 152 in adjacent stator plates 134 wheninterlocked and assembled. To allow for the combination of a series ofinterlocked stator plates 134, rivet holes 153 are formed in stator base140. Rivets (not shown) are inserted into the rivet holes 153 ofadjoining stator plate bases and secured via ball and peen hammering orother like method.

Assembled within two interlocking stator plates 134 is a wire coil 132.As shown in FIGS. 15 and 16, wire coil 132 comprises a preferably hollowcylindrical spool 156 having coil walls 158 extending radially outwardlyfrom each end of spool 156. The combination of the spool 156 and coilwalls 158 form an annular channel for receiving wire windings 160 thatare typically copper wire with varnish coatings or plastic covers forinsulation. Extending from windings 160 are wire leads 162 that are inelectrical connection with windings 160. Positive, negative and neutralleads are preferably provided for each coil 132. Wire leads 162 providea means to attach coil 132 to a power supply.

Positioned within, and in concentric relation with stator assembly 130is rotor assembly 125 shown in FIGS. 17-26. Rotor 112 has a centralthrough aperture 113 dimensioned to receive spindle 118. An eccentricbore 170 shown in FIG. 20 is formed about aperture 113 to receive ano-ring as described more fully below. A second rotor bore 172 is formedabout a distal end of aperture 113 and has a diameter greater than thediameter of bore 170 and a depth less than the depth of bore 170. Secondrotor bore 172 is provided to receive a radially extended base ofspindle 118 as described in detail below. Extending from a distal end ofrotor 112 is a spindle stop shoulder 174 that limits the range ofrotation travel of spindle 118 from a fully closed position to apreferably fully open position. The length of shoulder 174 can beadjusted to accommodate a wide range of angular travel distances forspindle 118.

An outer surface of rotor 112 is fixed to an inner wall 121 of rotormagnet 120 via interference fit, mechanical fit, friction fit, adhesiveor any other suitable means of securing a metallic cylindrical object toan inner wall of a ring like structure, as shown in FIG. 17. Preferably,rotor magnet 120 is preformed with alternating bands of polarity asshown in FIG. 26. The number of alternating band pairs of polaritydetermine the number of poles in the motor. The magnet shown in FIG. 26has twelve poles. An outer wall 123 of magnet 120 creates an air gapwith an inner wall of stator assembly 130 where magnetic flux isgenerated to cause rotation of rotor assembly 125.

As stated, spindle 118 is dimensioned to fit within the aperture andbores of rotor 112. FIGS. 22-24 show spindle 118 with a top cylindricalportion 180 dimensioned to fit within rotor aperture 113. Situateddistal to cylindrical portion 180 is radially extending base 182dimensioned to fit within rotor bore 172. A stop pin 184 is formed on orfixed to the perimeter of base 182 to engage shoulder 174 of rotor 113.The combination of shoulder 174 and stop pin 184 set the extreme travelpositions for spindle 118 in rotor 112. A spindle inlet bore 186 isformed in cylindrical portion 180 to receive fluids or gases directedthrough the metering valve. Proximal and distal spindle inlet ports 188and 189, respectively, are formed in the proximal and distal ends ofcylindrical portion 180 to allow for the passage of fluid or gasentering inlet bore 186 to exit cylindrical portion 180 and travelbetween cylindrical portion 180 and rotor 112. An annular channel 190 isformed about the plane occupied by distal spindle inlet port 189 toenhance the amount of fluid or gas traveling to the lower portions ofthe rotor/spindle assembly.

A spindle outlet bore 194 is formed in a bottom portion of spindle 118.Formed at a proximal end of outlet bore 194 are preferably threemetering ports 196 that are in fluid communication with outlet bore 194,and distal and proximal inlet ports 188 and 189. The use of threemetering ports in this embodiment allows for higher flow rates, lessfluid flow resistance and a more precise metering of fluid or gas inthat the range of travel from a full shut position to a full openposition can be increased to as much as 2400 of angular travel asopposed to the approximately 900 of travel of the previously describedembodiment.

To secure spindle 118 to rotor 112, a spindle washer and snap ring areused. Spindle 118 has a proximal annular channel 200 formed proximal toits top end to receive a snap ring 202. A washer 201 is provided aboutcylindrical portion 180 and between a top surface of rotor 112 and snapring 202. The combination of snap ring 202 against rotor 112 and thenesting of spindle base 182 in rotor bore 172 secures the axial relationof spindle 118 to rotor 112.

To provide a means to control the flow of gas or fluid through meteringports 196 a metering o-ring 210 is provided about the ports to controlfluid flow. Metering o-ring 210 sits in bore 170 such that the eccentricshape of bore 170 is reflected in metering o-ring 210 that conforms tothe shape of bore 170. Rotation of spindle 118 within rotor 112 causesmetering ports 196 to ride along the eccentric shape of metering o-ring210 which causes the ports to be open when registered with the circularportions of bore 170 and to be closed when registered with the flattenedportions of bore 170 as shown in FIG. 20. Metering o-ring 210 ispreferably made from heat resistant viton, moly filled whereas othero-rings described herein can be made from buna-n rubber. To protectmetering o-ring 210 from abrasion from the rotating base 182, a meteringwasher 212 is provided about cylindrical portion 180 and between base182 and metering o-ring 210.

To provide a fluid tight seal between the spindle and the metering valvehousing described below, a spindle o-ring 214 is provided about a distalend of spindle 118. A distal spindle channel 216 is formed in the distalend of spindle 118 to receive spindle o-ring 214.

A metering valve housing 220 is provided to house the combined statorassembly 130 and rotor assembly 125 as shown in FIGS. 34-44. Housing 220comprises a generally cylindrical body 221 having a central bore 222dimensioned to receive stator assembly 130. Extending axially from adistal end of housing 220 is a ridge 224. A preferably threaded wireaperture 226 is formed in ridge 224 to provide an exit for wire leads162. An outlet port 228 is formed substantially in a central portion ofridge 224 so as to be in fluid communication with central bore 222. Aninlet port 230 is formed in ridge 224 on a lateral end of ridge 224opposite the lateral end at which wire aperture 226 is formed. Inletport 230 is in fluid communication with central bore 222. Wire aperture226, outlet port 228 and inlet port 230 are preferably threaded aboutinner walls to accommodate fittings for pipe or other connections.Preferably, the outer radial sections 227 and 231, respectively, of thebores for wire aperture 226 and inlet port 230 extend partially downinto central bore 222 and extend radially outwardly into the wallsdefining central bore 222 so that wire and fluid inlet passages areformed when stator assembly 130 is placed in central bore 222.

A top end of housing 220 preferably has threading formed about an innerwall to receive a retaining nut 250 shown in FIGS. 38 and 39. Acylindrical seal cap 240 is provided to seal the top end of housing 220after the stator/rotor assembly is mounted in the housing. Seal cap 240has an annular cap channel 242 formed about an outer circumferentialedge of the cap to receive a housing o-ring 244 shown in FIG. 10. Acentral spindle receiving bore 245 is provided to stabilize the axialalignment of spindle 218, if necessary. Following the positioning ofseal cap 240 in housing 220, a cylindrical retaining nut 250 is torquedinto the top end of housing 220 by mating external threads 252 formed onthe outer perimeter of retaining nut 250. Retaining nut 250 ispreferably formed with bores or apertures 254 to receive torquing toolssuch as a spanner wrench as is well known in the art to torque retainingnut 250 into housing 220. Retaining nut 250 can be formed with a centralaperture 256 or can be a solid cylindrical plate.

In an alternative embodiment, housing 220 can be die-cast as shown inFIGS. 41-44. Components of the die-cast version that correspond to thecomponents of the machined version described above are designated withprime numbers that correspond to the numbers designating the componentsof the machined version. The primary difference between the versions isthat the die-case version is amenable to having mechanical fastenerbores formed in appendages 270 of housing 220′ to receive mechanicalfasteners (not shown) used to secure cap 240′ to housing 220′ viamechanical fastener bores 241 formed about the circumference of cap240′.

To provide a smooth exit channel for lead wires 162 that exit housing220, a gland nut 280 is provided with external threading that engagesthe internal threading of wire aperture 226 as shown in FIGS. 10, 27 and28. Gland nut 280 has a central aperture 282 for receiving wire leads162. A hex shaped flange 284 is provided to facilitate torquing of glandnut 280 into wire aperture 226. To provide a watertight seal to the wireexit port 226, a combination of a wire pass through seal 290 issandwiched between a pair of seal support plates 292. Both the supportplates and seal are formed with a plurality of apertures for passage oflead wires 162 through the components. To effectuate the seal, onesupport plate 292 is placed into the bottom of wire aperture 226followed by seal 290 and the second support plate 292. By torquing glandnut onto the second support plate 292 causes seal 290 to compressagainst the wall of wire aperture 226. Seal 290 is preferably made frombuna-n rubber and the support plates are preferably made fromglass-reinforced nylon.

To operate the metering valve, fluid or gas is allowed to flow intoinlet port 230. The fluid or gas proceeds down into the annular spacebetween stator 130 and housing 220. The gas travels to and enters theinlet bore 186 of spindle 188 and travels out of the bores 188 and 189into the annular gap between rotor 112 and spindle 118. Depending on theorientation of rotor 112 to spindle 118, the metering ports 196, ifopen, will allow the entry of the gas or fluid which travels up the exitport 194 of spindle 118 and out the exit port 228 of housing 220.

Having described the invention it should be understood that theforegoing description of the invention is intended merely to beillustrative thereof and that other modifications, embodiments andequivalents may be apparent to those who are skilled in the art withoutdeparting from its spirit. Having thus described the invention what weclaim as new and desire to secure by United States Letters Patent is:

1. A valve comprising: a spindle having an inlet bore extendinglongitudinally from a top end of the rotor with a radial inlet apertureand an outlet bore extending longitudinally from a bottom end of therotor with a radial outlet aperture; a rotor having a first boredimensioned to receive the spindle and a second bore in eccentricorientation to the first bore; an o-ring dimensioned to fit within thesecond bore of the rotor; a rotor cap having a cap bore dimensioned toreceive a top end of the rotor; a rotor gear press fitted onto a bottomsurface of the rotor; a mounting plate having a top surface to which therotor gear is affixed; a drive gear in synchronous orientation with therotor gear; a motor attached to a bottom surface of the mounting plateand having a shaft to which the drive gear is attached.
 2. The valve ofclaim 1 further comprising a second o-ring situated between the rotorand the spindle.
 3. The valve of claim 1 wherein the spindle comprises ahexagonal top to allow the spindle to be torqued into the mountingplate.